1. Field of the Invention
The present invention relates to a gallium nitride (GaN)-based semiconductor laser diode.
2. Related Background Art
Patent Document 1 discloses a Fabry-Pérot type semiconductor laser diode. An n-type semiconductor layer, a light emitting layer and a p-type semiconductor layer are stacked in the m-axis direction. The n-type semiconductor layer includes an n-type GaN cladding layer and an n-type InGaN layer, and the p-type semiconductor layer includes a p-type GaN cladding layer and a p-type InGaN layer. The refractive index difference between the cladding layers and the optical guide layers is 0.04 or more. Patent Document 2 discloses a laser device with the emission wavelength of 425 nm to 450 nm.    Patent Document 1: Japanese Patent Application Laid-open No. 2008-311640    Patent Document 2: Japanese Patent Application Laid-open No. 2002-270971